Merge pull request #171 from emmellsoft/master

Added waveshare-adda-board draft.

draft/overlay/waveshare-adda-board.md

@@ -0,0 +1,88 @@
+<!--
+---
+name: High-Precision AD/DA Board
+class: board
+type: adc
+formfactor: HAT
+manufacturer: Waveshare
+description: 8 channel Analogue to Digital Converter & 2 channel Digital to Analogue Converter
+url: http://www.waveshare.com/High-Precision-AD-DA-Board.htm
+schematic: http://www.waveshare.com/wiki/File:High-Precision-AD-DA--Schematic.pdf
+buy: http://www.waveshare.com/High-Precision-AD-DA-Board.htm
+image: 'waveshare-adda-board.png'
+pincount: 40
+eeprom: no
+power:
+  '1':
+  '2':
+  '4':
+  '17':
+ground:
+  '6':
+  '9':
+  '14':
+  '20':
+  '25':
+  '30':
+  '34':
+  '39':
+pin:
+  '11':
+    name: DRDY
+    mode: output
+    active: low
+  '12':
+    name: RESET
+    mode: input
+    active: low
+  '13':
+    name: PDWN
+    mode: input
+    active: low
+  '15':
+    name: CS0
+    mode: input
+    active: low
+  '16':
+    name: CS1
+    mode: input
+    active: low
+  '19':
+    mode: spi
+  '21':
+    mode: spi
+  '23':
+    mode: spi
+  '24':
+    mode: spi
+  '33':
+    name: Buzzer
+    mode: pwm
+  '31':
+    name: D0
+    mode: input/output
+  '32':
+    name: D1
+    mode: input/output
+  '33':
+    name: D2
+    mode: input/output
+  '34':
+    name: D3
+    mode: input/output
+-->
+#High-Precision AD/DA Board
+
+There's no AD/DA function on the Raspberry Pi GPIO interface, this may trouble you in the Pi development. However, it won't be a problem anymore. The High-Precision AD/DA Board allows you to add high-precision AD/DA functions to the Raspberry Pi.
+
+##Features
+
+- Onboard ADS1256, 8ch 24bit high-precision ADC (4ch differential input), 30ksps sampling rate
+- Onboard DAC8532, 2ch 16bit high-precision DAC
+- Onboard input interface via pinheaders, for connecting analog signal
+    - the pinout is compatible with Waveshare sensor interface standard, easy to connect various analog sensor modules
+- Onboard input/output interface via screw terminals, for connecting analog/digital signal
+- Features AD/DA detect circuit, easy for signal demonstration
+
+[Official Wiki page getting started on Linux](http://www.waveshare.com/wiki/High-Precision_AD/DA_Board)
+[Raspberry Pi AD/DA Board Library for Window 10 IoT Core](https://www.hackster.io/laserbrain/raspberry-pi-ad-da-board-library-for-window-10-iot-core-c8cc34 "www.hackster.io")